You have the 3S-FE more than likely...that engine has a fairly complicated system for controlling idle speed. Your best bet would be to just look at the idle screw (it's hidden underneath a little rubber cap that is just near the throttle body) and try turning that to see if it helps.
Check all the vacuum hoses as well...
As for your cold start problems...you could have a clogged cold start injector, or semi-leaky distributor cap, dodgy ignition leads -> there's quite a number of possibilities.